Crystals of fluoran compound, crystalline solvates thereof and process for their preparation

Abstract

Disclosed are a crystal and crystalline solvate of a fluoran compound represented by the formula ##STR1## wherein R 1 is ##STR2## and which are useful as chromogenic compounds in recording materials such as pressure-sensitive and heat-sensitive recording materials, a process for preparation of said crystal and said crystalline solvate, and recording materials comprising said crystal or said crystalline solvate.

What is claimed is: 
     
       1. A crystal of a fluoran compound represented by the formula (I): ##STR30## wherein R 1  in the formula (I) is: ##STR31## and the crystal has an X-ray diffraction diagram having a high peak at a diffraction angle (2θ) of 6.4° in X-ray diffraction analysis by the Cu-Kα beam, ##STR32## and the crystal has an X-ray diffraction diagram having high peaks at diffraction angles (2θ) of 20.3° and 20.5° in X-ray diffraction analysis by the Cu-Kα beam, ##STR33## and the crystal has an X-ray diffraction diagram having high peaks at diffraction angles (2θ) of 7.1°, 18.5°, 20.0°, 20.5° and 21.4° in X-ray diffraction analysis by the Cu-Kα beam, ##STR34## and the crystal has an X-ray diffraction diagram having high peaks at diffraction angles (2θ) of 16.5° and 20.4° and relatively high peaks at 11.9°, 17.8°, 18.3°, 19.2° and 20.0° in X-ray diffraction analysis by the Cu-Kα beam, or ##STR35## and the crystal has an X-ray diffraction diagram having high peaks at diffraction angles (2θ) of 16.3° and relatively high peaks at 19.7°, 20.1° and 21.4° in X-ray diffraction analysis by the Cu-Kα beam. 
     
     
       2. A crystalline solvate of a fluoran compound represented by the formula (I): ##STR36## wherein R 1  is ##STR37## and an aromatic hydrocarbon-based solvent, alcohol-based solvent or a ketone-based solvent. 
     
     
       3. The crystalline solvate of claim 2 wherein the aromatic hydrocarbon-based solvent is benzene, toluene, xylene, ethylbenzene, anisole or chlorobenzene. 
     
     
       4. The crystalline solvate of claim 2 wherein the alcohol-based solvent is isopropanol. 
     
     
       5. The crystalline solvate of claim 2 wherein the ketone-based solvent is acetone or methyl ethyl ketone. 
     
     
       6. The crystalline solvate of claim 2 wherein the fluoran compound has ##STR38## as R 1  in the formula (I) and the aromatic hydrocarbon-based solvent is benzene, toluene, o-xylene or anisole. 
     
     
       7. The crystalline solvate of claim 2 wherein the fluoran compound has ##STR39## as R 1  in the formula (I) and the aromatic hydrocarbon-based solvent is benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, anisole or chlorobenzene. 
     
     
       8. The crystalline solvate of claim 2 wherein the fluoran compound has ##STR40## as R 1  in the formula (I) and the aromatic hydrocarbon-based solvent is benzene, toluene or anisole. 
     
     
       9. The crystalline solvate of claim 2 wherein the fluoran compound has ##STR41## as R 1  in the formula (I) and the aromatic hydrocarbon-based solvent is benzene or toluene 
     
     
       10. The crystalline solvate of claim 2 wherein the fluoran compound has ##STR42## as R 1  in the formula (I) and the alcohol-based solvent is isopropanol. 
     
     
       11. The crystalline solvate of claim 2 wherein the fluoran compound has ##STR43## as R 1  in the formula (I) and the ketone-based solvent is acetone or methyl ethyl ketone. 
     
     
       12. A process for the preparation of a crystal of claim 1, comprising either (a) precipitating a fluoran compound of formula (I) in crystalline form from a solution of said fluoran compound in an organic polar solvent having a moisture content of 50% by weight or less and isolating the precipitated compound or (b) dissolving a fluoran compound of formula (I) in amorphous form in an organic polar solvent having a moisture content of 50% by weight or less and successively precipitating and isolating the fluoran compound in crystalline form. 
     
     
       13. The process of in claim 12 wherein R 1  is ##STR44## in the formula (I) and the crystal obtained exhibits high peaks at diffraction angles (2θ) of 20.3° and 20.5° in X-ray diffraction analysis by the Cu-Kα beam. 
     
     
       14. The process of in claim 12 wherein R 1  is ##STR45## in the formula (I) and the crystal obtained exhibits high peaks at diffraction angles (2θ) of 7.1°, 18.5°, 20.0°, 20.5° and 21.4° in X-ray diffraction analysis by the Cu-Kα beam. 
     
     
       15. The process of in claim 12 wherein R 1  is ##STR46## in the formula (I) and the crystal obtained exhibits high peaks at diffraction (2θ) of 16.5° and 20.4° and relatively high peaks at 11.9°, 17.8°, 18.3°, 19.2° and 20.0° in X-ray diffraction analysis by the Cu-Kα beam. 
     
     
       16. The process of in claim 12 wherein R 1  is ##STR47## in the formula (I) and the crystal obtained exhibits a high peak at a diffraction angle (2θ) of 16.3° and relatively high peaks at 19.7°, 20.1° and 21.4° in X-ray diffraction analysis by the Cu-Kα beam. 
     
     
       17. The process for the preparation of a crystal of a fluoran compound of claim 1 represented by the formula (I): ##STR48## wherein R 1  is ##STR49## 
     
     
       18. The process of claim 17 wherein the crystalline solvate of the fluoran compound is a solvate of benzene, toluene, xylene, ethylbenzene, anisole, chlorobenzene, isopropanol, acetone or methyl ethyl ketone. 
     
     
       19. The process of claim 17 wherein R 1  is ##STR50## in the formula (I) and is characterized by an X-ray diffraction diagram having a high peak at an diffraction angle (2θ) of 6.4° in X-ray diffraction analysis by the Cu-Kα beam, comprising conducting suspension treatment of the crystalline solvate of the fluoran compound of claim 11 in an organic polar solvent having a moisture content of 50% by weight or less and successively separating the resulting crystal. 
     
     
       20. The process of claim 19 wherein the organic polar solvent is alcohol. 
     
     
       21. The process of claim 17 wherein R 1  is ##STR51## in the formula (I) and the crystal exhibits high peaks at diffraction angles (2θ) of 20.3° and 20.5° in X-ray diffraction analysis by the Cu-Kα beam, comprising dissolving a crystalline solvate of a fluoran compound wherein R 1  is ##STR52## in the formula (I) and an aromatic hydrocarbon-based solvent is benzene, toluene, o-xylene or anisole in an organic polar solvent ; and successively precipitating and isolating the crystal from the resultant solution. 
     
     
       22. The process of claim 21 wherein R 1  is ##STR53## in the formula (I) and the crystal exhibits high peaks at diffraction angles (2θ) of 7.1°, 18.5°, 20.0°, 20.5° and 21.4° in X-ray diffraction analysis by the Cu-Kα beam, comprising dissolving a crystalline solvate of a fluoran compound wherein R 1  is ##STR54## in the formula (I) and an aromatic hydrocarbon-based solvent is benzene, toluene, o-xylene m-xylene, p-xylene, ethylbenzene, anisole or chlorobenzene in an organic polar solvent; and successively precipitating and isolating the crystal from the resultant solution. 
     
     
       23. The process of claim 17 wherein R 1  is ##STR55## in the formula (I) and the crystal exhibits high peaks at diffraction angles (2θ) of 16.5° and 20.4° and relatively high peaks at 11.9°, 17.8°, 18.3°, 19.2° and 20.0° in X-ray diffraction analysis by the Cu-Kα beam, comprising dissolving a crystalline solvate of a fluoran compound wherein R 1  is ##STR56## in the formula (I) and an aromatic hydrocarbon-based solvent is benzene, toluene or anisole in an organic polar solvent; and successively precipitating and isolating the crystal from the resultant solution. 
     
     
       24. The process of claim 17 wherein R 1  is ##STR57## in the formula (I) and the crystal exhibits a high peak at a diffraction angle of 16.3° and relatively high peaks at 19.7°, 20.1° and 21.4° in X-ray diffraction analysis by the Cu-Kα beam, comprising dissolving a crystalline solvate of a fluoran compound wherein R 1  is ##STR58## in the formula (I) and an aromatic hydrocarbon-based solvent, alcohol-based solvent, or a ketone-base solvent is benzene, toluene, isopropanol, acetone or methyl ethyl ketone in an organic polar solvent; and successively precipitating and isolating the crystal from the resultant solution. 
     
     
       25. The process of claim 21, wherein the organic polar solvent is an alcohol-based solvent or a ketone based solvent or acetonitrile. 
     
     
       26. A process for the preparation of a crystalline solvate of claim 2, comprising either (a) dissolving a crystal of the fluoran compound represented by the formula (I) in an aromatic hydrocarbon-based, alcohol-based or ketone-based solvent and successively precipitating and isolating the crystalline solvate or (b) dissolving a fluoran compound represented by the formula (I) in amorphous form in an aromatic hydrocarbon-based, alcohol-based or ketone-based solvent and successively precipitating and isolating the crystalline solvate.   
     
     
       27. The process of claim 26 wherein the aromatic hydrocarbon based solvent is benzene, toluene, xylene, ethylbenzene, anisole or chlorobenzene. 
     
     
       28. The process of claim 26 wherein the alcohol-based solvent is isopropanol. 
     
     
       29. The process of claim 26 wherein the ketone-based solvent is acetone or methyl ethyl ketone. 
     
     
       30. The process of claim 26 wherein R 1  is ##STR59## in the formula (I) and the aromatic hydrocarbon-based solvent is benzene, toluene, o-xylene or anisole. 
     
     
       31. The process of claim 26 wherein R 1  is ##STR60## in the formula (I) and the aromatic hydrocarbon-based solvent is benzene, toluene, o-xylene, m-xylene, p-xylene, ethylbenzene, anisole or chlorobenzene. 
     
     
       32. The process of claim 26 wherein R 1  is ##STR61## in the formula (I) and the aromatic hydrocarbon-based solvent is benzene, toluene or anisole. 
     
     
       33. The process of claim 26 wherein R 1  is ##STR62## in the formula (I) and the aromatic hydrocarbon-based, alcohol-based or ketone-based solvent is benzene, toluene, isopropanol, acetone or methyl ethyl ketone.